The present invention concerns an automatic dispenser of instantly cooked prepacked food. In particular, it concerns an automatic dispenser of spiced popcorn prepacked in sealed packets.
In the wide field of automatic food dispensers, the popcorn dispensing machines are still scarcely widespread, their little success being tied to technical and hygienic factors which will be examined in detail hereinafter. Nonetheless, the request for an automatic popcorn dispensing machine is, at least potentially, very high especially where there is a large flow of public, as in cinemas, sports establishments, discotheques and so on.
What characterizes, in particular, a popcorn dispenser in respect of other automatic food and drink dispensers, and also makes it so critical, is the fact that corn should be preferably kept raw, and then be popped just before being eaten, so as to be fragrant and appetizing. It is also fundamental for the corn seeds to be kept in such a dispenser in hygienically safe conditions and there should be no possibility of interaction between the cooking apparatus and the consumer; when popping corn seeds for domestic use, all these requirements are of course neglectable.
In fact, at home, the corn seeds are normally popped in boiling oil until they burst; they are then strained to remove the oil in excess, and salt or sugar is added to make them tasty. Evidently, such an operating sequence is quite easy to carry out manually, being fairly cautious so as to create no problems; in theory, it would be the ideal sequence which should be exactly followed also by the dispensing machine, failing which the popcorn obtained would not be tasty and thus be unsaleable.
Nevertheless, the popping in oil, as done at home, is unfeasible in the case of automatic dispensing machines, in that it would be necessary to dispose of large quantities of frying oil, which is subject to fast deterioration and which can no longer be used after a few times; without taking into account that it is quite unhealthy to keep fried oil in a container while waiting for the successive cooking operation.
To overcome this drawback, semi-automatic popcorn dispensing machines have been produced, which pop a large amount of corn seeds in a single step and subsequently dispense it in small doses. This technique can be advantageous if there is a high consumption of popcorn, whereby the popped and burst corn seeds are not kept in the machine for a long time with the risk of deteriorating in contact with air.
According to a different technique, a machine to pop corn seeds is fed with hot air produced by a resistor (as in EP-A2-265.361). However, the taste of popcorn treated in this way is not so appreciated as that of popcorn obtained with the traditional home technique. Moreover, the heat supplied by the resistor does not allow very short cooking times whereby, to make sure that a popcorn dispenser for the public is efficient and productive, it is indispensable to make it of large dimensions and to pop, also in this case, great quantities of corn which are then dispensed to the consumers in small doses.
In recent times, it has been thought to produce suitable packages for domestic use which contain, inside a sealed packet, a dose of corn for one person, with a predetermined amount of oil and spice. The single prepacked packet is heated with a heating source, swelling up as the corn seeds, bursting, expand inside the same.
Different versions of said practical, hygienic and long-life packages have been produced, according to the type of heat source adopted, and they all provide excellent results as far as the final product obtained. One of such packages has been particularly studied for use with domestic type microwave ovens (see EP-B1-545.611). In fact, if done at home, the popping of corn in such a prepacked packet, carried out in a microwave oven, involves no problems nor does it require any special precautions.
Viceversa, the use of such a prepacked packet in a microwave oven, associated to an automatic dispenser, causes a series of problems which have so far made it unproposable to produce a machine thus conceived.
To start with, the prepacked packet should be introduced in the oven in the correct position, namely in a position allowing the microwaves to act with the highest efficiency on the food to be cooked.
In particular, the prepacked packets specially meant for this type of oven comprise a sheet-metal insert which should remain under the food, in respect of the magnetron source of the oven, so as not to act as screen for the microwaves. Hence, the packets should be positioned into the oven in the right sense.
However, the possibility for the consumer to act inside or close to the oven should be positively avoided, as the microwave oven is a source of possible electrical discharges, or of high-frequency electromagnetic waves, which are harmful to a person's health. Besides, as known, special care should be dedicated to the safety of machines for public use.
The oven should thus be provided with openings--both to let in the prepacked packets and to let out said packets--which allow a fully automatic insertion and ejection of said packets without requiring human intervention.
Moreover, the automatic dispenser should guarantee the feeding of a single prepacked packet at a time, to avoid the simultaneous presence of several packets in the oven.
Finally, the cooking apparatus should be at the same time simple and highly efficient, so that the dispensing machine may be economically advantageous.